Newsflash: Shared house equity

We are interested in buying two neighboring houses — one we would own 100% and live in, the other we would split equity with other family members perhaps 50/50 and they would live in it. We would not live in the second house, but might share use of the yard etc. How would this work? Split the down payment, mortgage payments, and property tax but have the occupants pay all utilities? What about repairs/improvements to the house — would those need to be tracked and split 50/50? Would the occupants need to pay “rent” to us at 50% market rate?Please skip any of the “this is a bad idea” feedback. Simply trying to understand the financial logistics of an arrangement like this.Thanks!